Method of and machine for making heat-transmitting tubes



Oct. 14, 1930. 'w. J. STILL 1,

METHOD OF AND MACHINE FOR MAKING HEAT TRANSMITTING TUBES Filed Nov. 17, 1926 4 Sheets-Sheet l Oct. 14, w. J. sTILL. 1,7785

M AND idACHINE-FOR MAKING HEAT wnmsm'r'rme wass V Filed Nov. 17 1926 I 4 Sheets-Sheet 2 N/ D m I, k 0 I W. J. STILL METHOD OF AND HACHINEFOR MAKING HEAT TRANSMITTING TUBES Filed Nov. 1'7, 1926 4 Sheets-Sheet 3 Oct. 14, 1930. I w. J. STILL I 4 METHOD OF AND MACHINE FOR MAKING HEAT TRANSMITTING TUBES Filed Nov. 17, 1926 4 Sheets-Sheet 4 Patented Oct. 14, 1930 UNITED STATES PATENT OFFICE WILLIAM JOSEPH STILL, OF WEST EALING, LONDON, ENGLAND METHOD OF AND MAG HINE FOR MAKING HEAT-TRANSMITTING TUBES Application filed November 17, 1926, Serial No. 148,988, and in Great Britain November 21, 1925.

This invention relates to the manufacture of that class of heat transmitting elements which are composed of a tube upon which wire spirals are secured, and to the manufacture of a flat sided or ribbon like coil for such purposes.

A particular form of heat transmitting element to which the present invention is applicable is set forth in the specification forming part of my application bearing Serial No.

272,297, filed April 23, 1928.

The present invention comprises a method of forming wire spirals for heat-transmitting tubes according to which the wire is wound upon a mandrel in contact with an inclined surface which operates automaticaly to push the spiral off the mandrel as it is formed.

A further feature of the invention comprises a machine for making a heat transmit7 ting element having a coiled wire wound spirally around a tube, comprising a device for coiling wire to form a spiral on a non-rotating mandrel and for coiling the same on its edge on the periphery of the tube of the element simultaneously.

Figure 1 is a sectional viewof the winding head of the machine for making the wire ribbon and applying it to the tube element.

Figure 2 is a sectional view of the mandrel of the machine and a washer therefor.

Figure 3 illustrates by three views a clamp for securing the end of the wire.

Figure 4 is an elevational view of the complete machine viewed from theoperating position.

Figure 5 is a side elevation of the machine. Figure 6 is an enlarged end section illustrating the method of making the tube.

Figure 7 is a rear elevational section taken on line 77 of Figure 5. In the machine as illustrated by these drawings the ribbon is delivered to and wound upon the tube 1 with a double binding wire 7 within it.

In manufacturing this tube element the binding ends of the binding wire 7 are spot welded to the tube andthe edge of the ribbon 6 which makes contact with the tube is preferably milled or flattened so as to make a good contact with the tube surfacer If de-- manually to give the desired tension and is sirable the tube 1 may however, be spirally corrugated to form a seating for the edge of the ribbon 6 in which case the milling operation is not necessary. After the spiral ribbon has been wound over the whole length of the tube element the free end of the binding wire is spot welded to the tube 1 and it will be found that the ribbon is quite rigidly at-. tached. It is, however, necessary to ensure perfect heat conductivity and the final operation in the manufacture of the tube element is to solder on the ribbon to the tube by solder 8.

Upon reference to Figures 1 to 7 it will be seen that I have devised a machine for the purpose comprising a ribbon forming head consisting of a frame 10 carrying a hollow spindle 11 supported on ball bearings; this spindle carries a spool of wire 12 which is clamped against a friction disc 13 by the spring plate 14, this being held in place by the sleeve 15 which is locked by a bayonet catch on the sprindle 11.

The spool is surrounded by a dish16 which supports a guide tube 17, a mouth 18 and a tension plate 19 (see Figured) the tension plate gives a suliicient resistance to the motion of the wire to make the sides of the spiral ribbon flat and yet; insufficient to break the wire.

The spring plate 14 should not be alone used for this purpose because the tension produced by it is not constant but increases as the quantity of wire on the spool 12 diminishes because of the reduction of its ef fective radius.

The ribbonwinding operation is started by passing wire from the spool through the hole 18 inthe dish 16 and drawing it up under the tension plate19; this is adjusted held in place when adjustedby a screw 20. The wire 25 is then passed through a guide tube 21 and is then ready to be hooked around a hardened steel mandrel 22. It should be hooked on about 1" from a hardened washer 23 bearing on an inclined end of the hollow spindle 11 and up to which the coil will run. as soon as the spindle 11 starts turning, by this inclined washer the wire ribbon will be forced along the mandrel 22.

The mandrel 22 fits into a taper socket in a sleeve 24 forming a bearing in the hollow spindle 11 and its projecting part is flat in section as shown at Figure 2, the washer 23 being slotted to suit it and to enable the wire 25 to pass under the mandrel whilst the washer 23 rocks over it under the influence of the inclined rotating end of the spindle 11, and the backward thrust of the wire ribbon 26.

The heat transmitting tube 27 which is to be covered with the ribbon 26 is held at one end by the outwardly gripping; jaws of a spring chuck 28, mounted in the bearings of a traversing head 37, these aws are expanded by a cone 29 which is drawn into them by a fly-nut 30 (see Figures 1 and 5). This spring chuck 28 is made on the end of a hollow spindle 31 which is threaded through a gear wheel 32, various spindles being used to suit different tube diameters.

An ordinary scroll chuck may be fitted on the spindle 31 and used for a range of the larger sizes of tubes and draw in cone chucks may be used for the smaller sizes, so as to avoid the use of many spindles, but for standard work on one size of tube, th form shown is very suitable.

The gear wheel 32 is feathered to the spindle 31 and is driven from a gear wheel 33 mounted on a spindle 82, this is in turn driven by a gear wheel 34 which is mounted upon and driven by the splined screw (see ure 7 this splined screw runs the whole length of a bed 36 and traverses the head 37 withdrawing it from its initial position, as shown, towards the other en d of bed 36.

The screw is operated by the bevel 90 see Figure 5, and the sprockets 38 and 39 the former being feathered to the same bush as a pulley 40 and is driven by it; the sprockets 3S and 39 are removable to permit changes to be readily made in the ratio of speed between the ribbon making spindle 11 and the tube spindle 31, so as to suit the various diameters of heat transmitting tubes required to be made, it being evident that the larger the tube diameter, the slower must it revolve in order to wind the ribbon closely on to the tube; an idle sprocket 41 is provided to take up chain slack and permit a free interchanee of sprocket wheels. Any desired degree of ribbon stretching, beyond its close coiled formation can be obtained by the choice of suitable sprockets, coupled, if necessary, with the use of a larger or smaller belt pulley. Diameter does not however affect the pitch of the spiral the ribbon forms upon. the tube.

This pitch is controlled by the size of the rear wheel. 32 used on the spindle of the tube head 37, and by withdrawing this spindle and substituting a smaller gear a slower pitched spiral will be formed; the idle gear 33 can be adjusted in a slot 42 so as to mesh properly with the smaller gear.

The tube 27 which is to be wound is supported close to the mandrel 22, from which it receives the wire ribbon 26, by a busa in a fixed head 43 (see Figure 4); this head is bolted to the bed 36.

As the traversing head 37 which carries the chuck 28 passes down the bed 36 it rotates the tube 27 and draws it through the bush in the fixed head 43; the tube 27 thus remains closely supported by the head 43 no matter what position the traversing head 37 may be in.

In order to provide means for making a small flat surface on the flattened wire spiral 26 where it engages the tube 27 around which it is to be coiled a rotary milling cutter or other suitable device may be arranged under the mandrel 22 at a position between the washer 23 and the tube 27 on which the flattened wire s iral being wound. so that the flattened surface out on the spiral 26 will be formed during the movement of the flattened wire spiral 26 along the mandrel 22 to the tube 27 in which it is being wound. This milling cutter may be supported on an arm extending from the main frame 10 and be provided with means for raising and lowering it so that it can be adjusted for mandrels of different depths and to give the desired extent of tube engaging: surface on the spiral 2G. The cutter should be so revolved. that its cutting action will be towards the washer 23 so as to compress the coils of the wire spiral compactly together.

To commence operations a full spool 44 of binding; wire 25 is placed upon a bracket 45; a pin 46 on an arm 47 carrying); an eccentric 81 on which rotates the shaft 48 carrying the upper roller 49 of a pair of wire tensioning rollers 49 and 50 is withdrawn and the arm moved in the direction of the arrow on Figure 1. this rotates a shaft 48 in eccentric bearinns in which it is mounted and lifts the uproller 49 away from the lower one 50.

The end of the binding wire 25 ca n now be passed through the stationary sleeve 24 and under the mandrel. 22. it is then. hooked over a pin 51 on the spindle 31; this spindle is then put in motion by a clutch on the shaft above the ulley 40 and the arm 47 is restored to position as drawn.

The rotation of spindle 31 and tube 27 winds the binding wire past the closed rollers 49 and 50 and flattened wire spiral will. emerge from the mandrel 22; when this takes place the unflattened end is cut off and thrown away, and the new end secured to the tube 27 by spot welding, or by a clamp similar to that shown in detail on Figure 3 which consists of a ring 52 made of a bent strip of metal of which the ends are turned outwards and he d together by a tightening" collar 53. A belt 54 on the loose pulley 55 of the driving lltl mechanism is now pushed over to the fast pulley 56 thereof, and the spool dish 16 com mences to revolve and produce a wire spiral ribbon around the mandrel 22 and the bind ing wire 25 as this wire is now moving along the mandrel and being wound on to the tube 27 the wire ribbon is caught between it and the tube, and bound upon it with the tension caused by the rol ers 49 and 50.

The degree to which the wire ribbon 26 is stretched is determined by its rate of produc tion relative to the circumferential speed at Which the tube 27 revolves, whilst the pitch of the spiral is controlled by the relative speed of this tube and the traversing screw 35.

The wire ribbon 26 is wound on the tube until the traversing head 37 has withdrawn all save about 1% length of the tube through the bush in the tube arm 43, the ril bon head 37 is then stopped and the wire ribbon 26 cut near the washer 23, the tube 27 being kept turning. until the remaining end of the ribbon is securely bound upon the tube 27, and a couple of turns of the binding wire laid on.

The binding wire 25 is then secured to the tube 27 close to the end of the wire ribbon 26, the remainder cut off and a pedal 157 for operating the cable 91 of the cross slide 58 carrying the traversing table 36' depressed; this draws the slide 58 away from the man drel 22 leaving the end of the binding wire 25 protruding from it, it also withdraws the tube from the mandrel.

By loosening the fly nut and depressing a lever 59 on the traversing head 37 carrying a splined nut 92 this becomes free from the traversing screw and can be slid to the right when the end of the tube 27 will emerge from the bush on the fixed head 43, it can then be :readily removed, when the pedal 157 can be released and the slide 58 will return to its stop by virtue of a-spring 60.

To wind another tube the traversing head 57 will be pushed up against a stop 61, a new heat transmitting tube 27 will be inserted in the bush of the arm 43 and the fly 'nut 30 screwed home; when the end of the binding wire 25 protruding from the mandrel has been secured to the new tube 27 the tube and ribbon spindles can be restarted and the new tube will be covered as formerly described. V

The flattening of the binding wire 25 is .not absolutely essential but it is far easier to retain the wire ribbon on edge with a fiat, than with 'a round section, or the flattening effect maybe obtained by two wires side by side,

* and the rolls 49 and 50 produce a very constant tension of suitable amount on the wire 25. Adjustment for altering the degree of flatness of the binding wire 25 is provided on the lower roller spindle 62, the ends of which are carried in an eccentric sleeve. 80,;

such an angle with the tube 27 for'this adjustment an arm 63 (see Fig. 4), thereon, is provided with a screw 64 which can partially rotate it and thus bring it closer to or further from the upper roll-er 49. The spindle 62 of the bottom roller 50 see Fig. 1 is held in a clamping jaw 75 by set screws 76.

The drive for the ribbon forming head should be separate from that for the tube traversing head and their controls independ out, for whilst they may start together, they will be stopped at difierent times; a clutch control for the pulley 40 driven by the belt 65, is advisable, as it enables it to be belted from a drum long enough to allow for the movement of the slide 58; the ribbon head should however be drivenfrom a fast and loose pulley and 56 as shown, so as to avoid sudden acceleration or deceleration of the dish 16, as this might break the wire passing'through it or cause the spool 12 to overrun.

The tail 165 of a casting 66 carryingthe flattening rollers 49 and 50, not only prevents the sleeve 24 from rotating but by means of the pinch screws 67, see Fig. 4, in lugs on the main frame or headstock 10 isprovided for the adjustment of the mandrel 22, at that the wire ribbon 26' will most readily bind to this tube in an upright position; the best mandrel position is not usually exactly vertical and varies somewhat with the hardness of the wire used.

The wire guiding tube 17 is arranged to swing out of the path of the spool 12 in order to facilitate the changing of spools.

A stop 68, see Fig. 4, is provided for the cross slides 58 adapted to engage a weighted arm 69 carrying an adjustable weight 70 and which indicates the tension imposed upon the binding wire 25 and enables the operator to see that this is correctly adjusted; he can control this by putting an auxiliary tension on the wire 25 by means of a spring washer 71.

The spools should be pierced with sight holes 72 as shown, so that the operator may see how much wire remains upon it and judge if it is suflicient for another tube.

No indication has been given on the drawings of the spot welding attachment because such apparatus is well known, the insulatmg weldingv arm can however be readily attached to the tube arm 43 and be brought into contact with the binding wire 25 by means of a pedal 73 as indicated.

The table 36 (see Fig. 7) pivots on the trunnions 73" which are supported on arms on the cross slide 58, it can therefore be tilted by means of the adjusting screw 74 so as to bring the upper side of tubes of various diameters into line with the binding wire 25 as it issues from under the lower edge of the mandrel 22, the driving gear to;;the travs.

erse screw and head is not affected by such adjustment.

T he main spindle 1.1 is carried in the head stock by ball bearings 7'? and 78. The loose pulley is also carried by ball bearings '[9 on the main spindle 11.

hat i. claim and desire to secure by Letters Patent is 1. A method of making a tubular heat transmitting element, consisting in coiling a wire on a fixed mandrel to form a ribbon spiral, and at the same time coiling the ribbon on its edge on the periphery of a tube.

2. A method of making a tubular heat transmitting element, consisting in coiling a wire on a fixed mandrel to form a hollow ribbon spiral, and at the same time passing a binding wire through it and coiling the ribbon edgewise together with the contained binding wire on a tube and fixing the binding wire to the tube.

3. A machine for forming a wire spiral and for simultaneously winding it spirally round a tube together with a binding wire, comprising a fixed headstock, a wire coiling device, a hollow spindle, a fixed mandrel, binding wire feeding mechanism, and means for rotating the tube and moving it axially, the binding wire being fed through the spindle and a longitudinal passage in the mandrel and through the spiral being formed and While it is being coiled round the tube.

4. A machine for formin a spiral wound ribbon of wire and for simultaneously winding it spirally edgewise round a tube, comprising a fixed headstock, a rotating head operating in the fixed headstock and carrying the ribbon forming wire, a fixed mandrel having a cross section of shape to form the spiral ribbon, means for rotating the tube and moving it axially at the same time, the ribbon forming mandrel being arranged at right angles to the rotating tube and so as to deliver the spiral ribbon edgewise onto the tube, and the mechanism for rotating the wire carrying head being rotated simultane ously with that rotating the tube.

5. A machine for forming a hollow spirally wound wire ribbon and for simultaneously winding it spirally edgewise round a tube together with a contained binding wire, comprising a fixed headstock, a rotating head op erating in the fixed headstock and carrying the ribbon forming wire. a fixed mandrel having a shape to form the hollow ribbon, means for moving the tube axially and rotating it at the same time, means for feeding the wire along a passage in the fixed mandrel into the hollow spiral ribbon, the ribbon forming mandrel being arranged at right angles to the rotating tube and so as to deliver the spiral ribbon edgewise on to the tube, and the mechanism for rotating the wire carrying head being rotated simultaneously with that rotating the tube.

6. A machine for forming a hollow spirally wound wire ribbon and for simultaneously winding it spirally edgewise round a tube together with a contained binding wire, com prising a fixed headstock, a rotating head operating in the fixed headstock and carrying the ribbon forming wire, a fixed mandrel having a shape to form the hollow ribbon, means for i'noving the tube axially and rotating it at the same time, tension rollers for feeding the wire along a passage in the fixed mandrel into the hollow spiral ribbon, the ribbon forming mandrel being arranged at right angles to the rotating tube and so as to deliver the spiral ribbon edgewise on to the tube, and the mechanism for rotating the wire carrying head eing rotated simultaneously with that rotating the tube and that driving the feed rollers.

7. A machine for forming ahollow spirally wound wire ribbon and for simultaneously winding it spirally edgewise round a tube together with a contained binding wire, comprising a fixed headstock, a rotating head operating in the fixed headstock and carrying the ribbon forming wire, a fixed mandrel having a shape to form the hollow ribbon and provided with an inclined surface, means for moring tl e tube axially and rotating it at the same time, means for feeding the wire along a passage in the fixed mandrel. into the hollow spiral ribbon. the ribbon forming manorel being arranged at right angles to the rotating tube and so as to deliver the spiral ribbon edgewise on to the tube, and the mechanism for rotating the wire carrying head being rotated simultaneously with that rotating the tube the incline surface being arrangec to push the spiral ribbon ofi its mandrel while it is being formed.

8. A machine for forming a hollow spirally wound wire ribbon and for simultaneously winding it spirally edgewise round a tube together with a contained binding wire, comprising a fixed headstock a rotating head operating in the fixed headstock and carrying the ribbon forming wire, a fixed mandrel having a shape to form the hollow ribbon, and provided with an inclined surface covered with a washer, means for moving the tube axially and rotating it at the same time, means for feeding the wire along a passage in the fixed mandrel into the hollow spiral ribbon, the ribbon forming mandrel being arranged at right angles to the rotating tube and so as to deliver the spiral ribbon edgewise on to the tube, and the mechanism for rotating the wire carrying head being rotated simultaneously with that rotating the tube, the washer on the incline surface being arranged to push the spiral ribbon off its mandrel while it is being formed.

9. A machine for forming a hollow spirally wound wire ribbon and for simultaneously Winding it spirally edgewise round a tube,

together with a contained binding wire, comprising a fixed headstock a rotating head, operating in the fixed headstock and carrying the ribbon forming Wire, a fixed mandrel having a shape to form the hollow ribbon, means for moving the tube axially and rotating it at the same time, wire tension adjusting eccentrics, wire feeding rollers for feeding the wire along a passage in the fixed mandrel into the hollow spiral ribbon and rotating on the wire tension adjusting eccentrics, the ribbon forming mandrel being arranged at right angles to the rotating tube and so as to de liver the spiral ribbon edgewise on to the tube, and the mechanism for rotating the wire carrying head being rotated simultane ously with that rotating the tube. a

10. A machine for forming a spiral wound ribbon of wire and for simultaneously winding it spirally edgewise round atube, com prising a fixed headstock a rotating head op- 'erating in the fixed headstock and carrying the ribbon forming wire, a fixed mandrel having a cross section of shape to form the spiral ribbon, nut and screw mechanism :for traversing the tube axially and spur gearing for rotating the tube, the ribbon forming mandrel being arranged at right angles to the rotating tube and so as to deliver the spiral ribbon edgewise on to the tube, and the mechanism for rotating the wire carrying head being rotated simultaneously with that rotating the tube and the spur gearing rotating the tube being rotated by the screw traversing the tube.

11. A machine for forming a spiral wound ribbon of wire and for simultaneously winding it spirally edgewise round a tube, comprising a fixed headstock, a rotating head operating in the fixed headstock and carrying the ribbon forming wire, a fixed mandrel having a cross section of shape 'to form the spiral ribbon, nut and screw mechanism for traversing the tube axially and spur gearing for rotating the tube, the ribbon forming mandrel being arranged at right angles to the rotating tube and so as to deliver the spiral ribbon edgewise on to the tube, and the mechanism for rotating the wire carrying head being rotated simultaneously with that rotating the tube and the spur gearing rotating the tube being rotated by the screw traversing the tube and provided with removable members replaceable by others to vary the pitch of the spiral on the tube.

12. A machine for forming a spiral wound ribbon of wire and for simultaneously winding it spirally edgewise round a tube, comprising a fixed headstock, a rotating head operating in the fixed headstock and carrying the ribbon forming wire, a fixed mandrel having a cross section of shape to form the spiral ribbon, means for rotating the tube and moving it axially at the same time, the ribbon angles to the rotating tube and so as to deliver the spiral ribbon edgewise on to the tube, and the mechanism for rotating the wire carrying head being rotated simultaneously with that rotating the tube, means being also provided for moving the rotating tube to and from the mandrel.

13. A machine for forming a hollow spirally wound wire ribbon and for simultaneously winding it spirally edgewise round a tube together with a contained binding wire, comprising a fixed headstock a rotating head operating in the fixed headstock and carrying the ribbon forming wire, a fixed mandrel having a shape to form the hollow ribbon, means for moving the tube axially and rotating it at the same time, means for feeding the wire along a passage in the fixed mandrel into the hollow spiral ribbon, the ribbon forming mandrel being arranged at right angles to the rotating tube and so as to deliver the spiral ribbon edgewise onto the tube, and the mechanism for rotating the wire carrying head being rotated simultaneously with that rotating the tube, means being also provided for moving the rotating tube to and from the mandrel.

14. A machine for making a wire covered tubular heat transmitting element, comprising means for coiling wire on a non-rotary mandrel to from a fiat ribbon spiral and means for coiling the fiat ribbon spiral edgewise on the tube of the element, and means whereby both operations are performed simultaneously.

In witness whereof I aflix my signature.

WILLIAM JOSEPH STILL.

forming mandrel being arranged at right 

